1. Field of the Invention
The present invention relates to a method for adhering together components that are molded from synthetic resin.
2. Description of the Related Art
A component cam be produced from synthetic resin to have an intricate interior structure by first forming a plurality of simple parts and then adhering the parts together into an integral unit to form the synthetic resin component. One example of a synthetic resin component with an intricate interior structure is an ink jet head used in an ink jet printer. Ink jet heads eject ink droplets having a very small volume of about 30 pl to 100 pl. Therefore, ink jet heads must have ink chambers for holding with an extremely small volume of the ink liquid.
Here, an explanation will be provided for manufacture of an ink Jet head used in an ink jet printer. The nozzle portion of the ink jet head is formed from an oscillation member and a molded member as well as other members. The molded member includes ink chambers for holding ink and nozzles through which the ink is elected. First, each of these different members is formed by injection molding techniques. Then, the members are adhered together using an adhesive.
It has also been proposed to produce a doped cement for use as the adhesive by dissolving the same material as that of the molded member in a solvent. When this method is used, solvent remains in the adhesive when the two members are adhered together. The solvent is totally evaporated after the two members are adhered together. However, bubbles are always generated in the adhesive layer when the solvent is evaporated In this manner. These bubbles degrade sealing characteristic of the adhesive. Therefore, this method of connecting members together is not well-suited for applications, such as ink jet heads, which require a complete seal over areas 80 microns wide. Further, this method results in only a relatively weak connection between the two pieces adhered together.
The adhesive used to connect together two molded resin pieces is generally produced by specialist companies. Generally, such adhesive is made from a material different from the material of the molded pieces. However, because ink jet heads have such a complicated and intricate structure, when two or more pieces are fixedly connected together to produce an integral head, a variety of problems regarding adhesive strength and precision arise because the characteristics of the adhesive layer are different from the characteristics of the resin member. For example, the pieces can separate from each other. Also, the difference between thermal expansion of the members and the adhesive, residual adhesive warping of the completed component, and adhesive sticking out from between the adhered members are problems relating to adhesive strength and precision.
Resin members with intricate structures are often adhered together using an adhesive formed in a sheet shape. However, the adhesive has low resistance to corrosion by ink.
Heads are often formed in an integral shape, that is, with a monocoque structure, using injection molding or blow molding techniques. However, these techniques not suitable for forming print heads with intricate and complicated structures.
The component resulting from adhering a plurality of resin members together and having intricate and complex sealed construction must have a complete seal at the adhesive layer portion.